1. Field of the Invention
This invention relates to a combined leveling device and laser pointer, particularly to one which has a laser light source unit removably associated with a leveling device.
2. Brief Description of the Related Art
It is known to combine a leveling instrument with a laser pointer for producing a linear projection image on the surface of an object or a wall so as to provide a marking line of predetermined inclining angle relative to a horizontal line. Based on the marking line, woodwork can be formed with inclined surfaces of predetermined angles.
Referring to FIG. 1, an instrument of the above-mentioned type is shown as having an elongated body 1 of rectangular cross-section with one end portion provided with a laser pointer 2 and the other end provided with an angle-measuring device 3. A bubble tube 4 is mounted to an intermediate part of the elongated body 1. The laser pointer 2 has a rotary seat 2a which holds a laser light source 2b and a hologram 2c disposed in front of the laser light source so as to produce a linear projection image on the surface of an object or a wall. A stationary graduated disk 2d is provided around the rotary seat 2a, and the rotary seat 2a may be rotated to an angle by referring to the graduations on the graduated disk 2d for adjustment of the inclination of the linear projection image relative to a horizontal line. The angle-measuring device 3 includes a circular housing 3a which is mounted rotatably on the body 1 and which houses a second bubble tube 3b. A pointer 1a is mounted to the body 1 and graduation marks are provided along the circumference of the circular housing 3a.
In use, the planar face 1b of the bottom side of the body 1 is placed on the surface of an object and is used as a reference face for the laser pointer 2 and the angle-measuring device 3. The laser pointer 2 is used to produce a linear projection image, while the angle-measuring device 3 functions to measure the angle of an inclined surface. The bubble tube 4 is used to determine whether or not a surface is horizontal. Although the instrument as mentioned above is multi-functional, it is still unsatisfactory because the delicate and expensive laser light source unit 2b is not detachable from the support body 1 of the instrument when it is not in use. Since the instrument is used in carpentry where it is not unusual for the instrument to be subjected to impact forces induced upon being dropped or upon collision, the laser light source unit is prone to damage.